Organic peroxide and hydroperoxide herbicides



Patented Oct. 27, 1953 ORGANIC .PEROXIDE AND HYDROPERQXIDE HERBICIDES Lyle D. Goodhue and Carolyn E. Tissol, Battles- 'ville, 01th., "assignors to Phillips Petroleum Company, a nonparation of Delaware N Drawing. Application December-.20, 1919, Serial No. 134,124

.-8.-Claims,.

This invention relates to herbicidal compositions, that is, weed killers. I he term weed includes any plant which persists in growing where it is not wanted. Thus, the use of the term weed is broad enough to include not only plants 5 and 'thefikeiWhenR is an aryl, alkary'l, or aralkyl harmful to man oranimal such as bull=nettle,rag group, typical compounds include methyl ,nitroweed and the like, but also otherwise desirable phenyl peroxide, methyl .p-chlorophenyl peroxide, plants such as lawngrasses growing on driveways, methyl phenyl peroxide, methyl methoxyphenyl etc. In one of its aspects the invention relates to peroxide, methyl ,isopropylbenzene peroxide, a herbicidal composition containing as oneiof its tertiary-,butyl 'isopropylbenzene peroxide and the efiective ingredients a peroxide or organic hydrolike. WhenR is cycloalkyl or cycloalkenyl, typical peroxide or an alkali metal salt of said hydrocompounds include propyl cyclohexyl peroxide, peroxide. In another of its aspects, the invention methyl cyclopenjtenyl peroxide, tertiary-buty'l relates to a herbicidal composition which, in adcycloocltyl peroxide and the like. 'When ,R is an dition to a peroxide or organic 'hydroperoxide or acyl radical a typical compound is tertiary-butyl an alkali metal salt of said hydroperoxide, also benzoyl peroxide. contains certain other ingredients which are novel The lhydroperoxide compounds which can be in respect of their inclusion in a herbicidal comused can 'berepresented'by the following general position. formula It has been found that a :peroxide or organic hydroperoxide or an alkali metal .salt of said hy- 0 Ox droperoxide, applied in certain minimum concentrations to plants, will cause very quick killing of the plants. wherein R may be hydrogen, a hydrocarbon An Object of this iIlVentiOIl is to provide anovel radical or a substituted hydrocarbon radical effective ingredient for a herbicidal composition. and t th may b lik or diff nt It is another object of this invention to provide or t a form a oarbooyolio ring or t 's a p d r an hyd p d or a alkali may beincludedin a carbocyclic structure; X may metal salt of said hydrop x as an effective be hydrogen or an alkali metal atom. Not more ingredient for a herbicidal composition. still anthan two Rs may be hydrogen at the same time. other object of this invention is to provide a The sum-of the carbon atoms in the R groups will e bi d composition Containing a P d beat least three and not more than 30 although organic hydroperoxide or an alkali .metal 188,113 Of higher molecular weight compounds may be temsaid hydroperoxide in admixture with certain ployedif i d other materials the use of which is novel in a Also according to this invention certainspecific herbicidal composition. A further object :of the bi ti of one or more of t hydmpemx invention is to provide a her i i al m i i ides, or-one or more of their salts, can be used or c nt inin a per xid or r n hydroperoxide admixed with certain other materials, set forth and/Oran alkali metal-salt of said hydroperoxide bemw, t yield h h efficacious herbicidal as Well as another material which specifically 40 po iti n improves the herbicidal efiiciency of'the composi- Typical compounds applicable to the present tion. invention when ,R is an alkyl or an alkenyl group Acoordine to thi inv i n, there is p v include trimethylhydroperoxymethane (tertiarya herbicidal composition containing as an .efiecbut l 'hydroperoxide) dimethylpropenylhydrotiv in d nt h r of a p r xid o or ni hyperoxymethane, and the like. When R is an aryl, droperoxide-or an alkali metal saltofsaidhydroalkaryl, r an aralkyl roup, typical compounds peroxide. include 'dimethyl (nitrophenyl) hydroperoxy h p roxide c mpounds which can be used can methane, dimethylphenylhydroperoxymethane be represented by the following general formula isopropylbenzene hydroperoxide), dimethyl ROOR phenylpropy'l) hydroperoxymethane and dimethyl (butenylp'henyl) hydroperoxymethane. Wherem R may hydrogen a hydrPcarbon WhenRis cycloalkyl or cycloalkenyl, typical comradical or a substituted hydrocarbon radical and paunds include 1dimethylcyclohexylhydrOpel-0X37- the He may be the same or dliferent. Th Sum methane, dim-ethylcyclopentenylhydroperoxy of the carbon atoms in the R groups W111 usually methana, and dimethylcyclooctylhydwpemxy not be greater than although methana When .two R s form a hydro- We h C p u d y be employed if desiredgenated polynuclear residue, tetralin hydro- W n n R s y g and n R is .alkyl, comperoxide is a typical compound. Other hydropounds of this type are called hydroperoxides. i peroxides which can .be employed are cumene Typical P xid compo nds ppl bl to h hydroperoxide, chlorocumene hydroperoxide,

2 present invention when R is hydrogen, an alkyl or an alkenyl group include hydrogen peroxide, tertiary-butyl ,isopropyl peroxide, tertiary-ibutyl propyl peroxide, tertiary-butyl propenyl peroxide methoxycumene hydroperoxide, and chlorodiisopropylbenzene hydroperoxide.

The compounds mentioned herein are effective for the eradication of noxious or undesirable weeds when applied thereto in any suitable form such as solutions, powders, creams, aerosols, as pure compounds, whether in crystalline or liquid, or in emulsion form, or as peroxide or as hydroperoxide concentrates. We have found that it is convenient to dissolve a peroxide or a hydroperoxide of the types disclosed above in a suitable solvent or otherwise employ it in a suitable carrier and to apply the composition so formed. Solvents or carriers which we have found applicable to the present invention include those which are substantially inert with respect to the active herbicidal ingredient. Among the materials which have been found useful for this purpose may be included kerosene, naphthas, and hydrocarbons boiling preferably above atmospheric temperatures, petrolatum, liquid polybutadiene, and others. In some instances it may be desirable to employ a solvent medium or carrier which of itself displays a toxic effect on higher plant life and thus gain the benefit of the combined toxicity of both substances at a single application.

If the active herbicidal ingredient is used in a medium having substantially no toxic properties such as petrolatum or an isoparaffinichydrocarbon fraction boiling between 360 and 410 F. at a 760 mm. sold as Soltrol 140, the lower effective limit appears to be about one weight per cent. However, when a toxic solvent is employed; the concentration may be correspondingly decreased. In this case the lower limit appears to be about 0.1 weight per cent. We prefer to use at least one weight per cent as a minimum concentration whether or not the solvent happens to display herbicidal activity. There is no upper limit to the concentration which may be employed, except that dictated by economy.

It is to be noted at this point that the effectiveness of the compounds of this invention appears to be due in large measure to the fact that they have the property of being able to penetrate into the conducting tissue of the plant. The compounds of the invention therefore appear to fit the definition of translocated or systemic herbicides. They do not merely injure the plant at the point of contact but move to other parts of the plant and destroy it from within.

It is an advantage of our novel herbicides that they are quick acting, often destroying plants to which applied within a period of about one hour. It is a further advantage of our novel herbicides that they do not render the soil sterile over which applied.

Compositions containing a compound of the present invention as a principal herbicidal ingredient may be applied for their intended purpose in several different ways. The most advantageous and presently preferred way, especially when treating large areas, is to spray a liquid composition on the leaves of the plants to be exterminated. This method takes advantage of the normal path taken by naturally occurring taining herbicidal compositions which are eifective for the practice of our invention:

Example I Parts Cumene tert.-buty1 peroxide 4 Stoddard solvent 96 Example II Cumene isopropyl peroxide is used instead of the Certain easily grown plants are good indicators of the herbicidal action of chemicals and can be used for the laboratory testing of herbicides. Black Valentine and black Wax beans between one and two weeks old were used in the following examples which will serve to illustrate the eiiectiveness of the compositions of our invention.

Example VII About 0.05 ml. of the composition of Example III was applied to each leaf of four young bean plants. Severe burning of the plants was observed 24 hours after application.

Example VIII The experiment of Example VII was repeated using a one per cent solution of tert-butyl benzoyl peroxide. Burning of the plants was observed 24 hours after application.

Example IX The experiment of Example VII was repeated using a one per cent solution of cumene tort.- butyl peroxide. Severe burning of the plants was observed 24 hours after application.

Example X Example XI Parts Isopropylbenzene hydroperoxide 4 Stoddard solvent 96 Example XII Diisopropylbenzene hydroperoxide was used instead of the isopropylbenzene hydroperoxide of Example XI.

Example XIII Parts Isopropylbenzene hydroperoxide 4 Petrolatum 96 5 Example XIV Diisopropylbenzene hydroperoxide was used instead of the isopropylbenzene hydroperoxide of Example XIII.

Example X V Tertiary:butylisopropylbenzene hydroperoxide was used instead of the isopropylbenzene hydroperoxideof Example XIII.

Example X I Par Isopropylbenzene hyd per x de e 7 4 Polybutadiene '-'-*T 96 Exampl 1.5. VII

Tertiary-butylisopropylbenzene hydroperoxide is used instead of the isopropylbenzene hydroperoxide of Example XVI.

Example XVII ,1

Parts Tertiaryvbutyl hydroperoxide 4 Hydrofluoric acid soluble oil, y ,p 96

Example XIX ,Isopropylbenzene hydroperoxide was used. instead of the tertiary-butyl hydroperoxide of Example XVIII.

The following additional examples serve to illustrate the effectiveness of the compositions of the invention.

Example XX The composition oi Example XI wa spr y d on a field test plot and compared with a control As stated, certain easily grown plants are good indicators of the herbicidal action of chemicals and can be used for the laboratory testing of herbicides. Black Valentine and black wax beans between one and two weeks old were used in the following examples Example XXI Approximately 0.5 gram of the composition of Example XIV was applied to the stems of young bean plants with a glass stirring rod. All parts of the plants above the treatment were killed in five to six hours after the treatment. Translocation up into the leaves was observed.

Example XXII The experiment of Example XXI was repeated using the composition of Example XV. All parts of the plants above the treatment were killed in five to six hours. Translocation up into the leaves was observed.

Example XXIII An appropriate 0.1 gram portion of a concentrate containing 60 weight per cent of tertiary-butyl hydroperoxide was applied to the stem of a young bean plant. The tissue under the treated portion collapsed within an hour.

The. use or sprouting Zenith rice as n indicator .oI herbicidal action is reported in the rolllowing examples. The method consists in placing a small amount .of the chemical (1 to 20m.) the center of a nine cm. filter paper previously placed in a 10 cm. pet-r1 dish. Five. to six c. of water was added and ten plump kernels of ice were placed in a circle around the chemical. The petri dishes were covered and placed at 70. E. to sprout the rice. An untreated check group was always prepared and run simultan o sly with the tests. The ratio of the rowth of the stems s roots in the treated to those in the untreated dishes is used as the criterion. Readings for the following tests were made on the seventh day.

Example XXIV On sprouting rice tertiary-butylisopropylbenzene hydroperoxide at five mg. in the petri dish test prevented growth.

Example XXV On sprouting rice diisopropylbenzene hydroperoxide at five mg. in the petri dish test prevented ro th Ex mp e X I Qn sprout n ri e isopronyl ennenc hydroneronide at five mg. allowed only 0.5 the owth of the check.

parent compounds, not hydroperoxides, had no efieot upon weeds. It will be recognized'by those skilled in the art that comparison of a plants condition after a number of hours, for example of the order of five hours, with its condition after a further number of hours. such as twenty four is rather difficult. Thus the seemingly illogical results in Number '7 are thus explained.

In the tests summarized below the compounds were dissolved in mineral oil to provide a concentration of 1 per cent based on hydroperoxide and 0.05 ml. of this solution was applied to one leaf of each of four young bean plants. Since the hydroperoxides were obtained as solutions in the parent hydrocarbon, checks were made by applying mineral oil solutions of the parent hydrocarbon alone. For purposes of comparison, cumene hydroperoxide was tested in a similar manner. Data on these tests are tabulated below.

one.

No. Compound Tested (percent) 5 hrs. 24 hrs.

1 Chlorccumene Hydroperoxidc. 1. 0 M M 2 Ghlorocumene (not a hydro l0. 0 O O peroxide).

3 Cumene Hydroperoxlde in 2.. 1.0 81- SH- 4 Chlorodiisopropylbenzene Hy- 1. 0 M+ M+ droperoxide.

5 Chlorodiisopropylbenzene 5.9 O 0 (not a hydroperoxide) 6 Oumene Hydroperoxide in 5 1. 0 M M 7 Mehoxycumene Hydroperox- 1.0 S M 8 Methoxycumene (not a hydro- 8.3 0 O peroxid 9 Cumene Hydropcroxide in 8... 1.0 M M 10 Cumene Hydroperoxide in oil 1. 0 SH 81+ 1 S=Severe; M=Moderate; Sl=S1ight; O=Nonc.

However, the five hour observations are conclusive of the effectiveness of the compounds employed if at that time noticeable modification has occurred.

' Reasonable variation and modification arepossible within the scope of the foregoing disclosure and the appended claims to the invention the essence of which is that certain peroxides and hydroperoxides, as well as alkali metal salts of said hydroperoxides, have been found effective as weed killers.

We claim:

1'. The method of destroying a plant which comprises applying to said plant a herbicidal amount of a material selected from the group consisting of a peroxide of the formula wherein each R is selected from the group consisting of a hydrocarbon radical and a substituted hydrocarbon radical and wherein the sum of the carbon atoms in the R groups is not in excess of 25, and an organic hydroperoxide of the formula wherein each R is selected from the group con sisting of a hydrocarbon radical and a substituted hydrocarbon radical and wherein the sum of the carbon atoms in the R group is not in excess of 25. 3. The method of claim 1 wherein the mate- 8 rial is an organic hydroperoxide of the formula R R-(J-O-O-X wherein each R is selected from the group consisting of hydrogen, a hydrocarbon radical, a substituted hydrocarbon radical, and a carbocyclic ring wherein two Rs are included in said carbocyclic ring; X is selected from the group consist ing of, hydrogen and an alkali metal atom; not more than two Rs shall be hydrogen at the same time and the sum of the carbon atoms in the R groups shall be at least 3 and not in excess of 30.

4. The method of destroying a plant which comprises applying to said plant a herbicidal amount of tert.-butyl benzoyl peroxide.

5. The method of destroying a plant which comprises applying to said plant a herbicidal amount of isopropylbenzene hydroperoxide.

6. The method of destroying a plant which comprises applying to said plant a herbicidal amount of a diisopropylbenzene hydroperoxide.

'7. The method of destroying a plant which comprises applying to said plant a herbicidal amount of tertiary-butylisopropylbenzene hydroperoxide.

8. The method of destroying a plant which comprises applying to said plant a herbicidal amount of tertiary-butyl hydroperoxide.

LYLE D. GOODHUE. CAROLYN E. TISSOL.

References Cited in the file of this patent FOREIGN PATENTS Country Date France May 30, 1927 OTHER REFERENCES Number 

1. THE METHOD OF DESTROYING A PLANT WHICH COMPRISES APPLYING TO SAID PLANT A HERBICIDAL AMOUNT OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF A PEROXIDE OF THE FORMULA 